The frame has not been altered, so the gun is basically is still a bp gun, all responders are right that the pistol can be shipped legally if the cylinders are packaged separately. You have to phyically alter the frame(Loading Groove) to be outside the law to sell. Been there, done that, Sold and bought one or more like seller's but were shipped separately from cylinder. Even here in Commiefornia.
BTW that is a good price right now for the frame and the cylinders. But I wouldn't bid against someone if I knew who they were, just ain't the cowboy way.